The present invention pertains to the field of visual display techniques for computer systems. More particularly, the present invention relates to techniques for generating stereoscopic images for virtual reality based applications.
Modern computer systems are capable of generating images with a high degree of realism. Traditional computer display techniques have achieved realism by generating two-dimensional (2-D) views of three-dimensional (3-D) scenes or data. However, advancements in virtual reality technology and in computer processing power have drawn considerable interest to technology for generating 3-D images of scenes or data. Such technology is highly desirable for use in many applications, particularly in computer games and in complex, real-world simulations.
The manner in which the human brain interprets visually-perceived objects in 3-D is well-understood. The brain perceives objects in 3-D, because the eyes detect images in stereo. A stereo effect is caused by the differences between the images detected by the left eye and the right eye due to the separation between the two eyes. Consequently, it is well known that the perception of 3-D can be provided artificially by generating two spatially-offset 2-D images of the same subject and providing these images separately to the left and right eye.
Regardless of the medium used, existing 3-D techniques each generally employ some mechanism to ensure that each eye sees only the appropriate one of the two views. Various approaches have been used to provide this function, such as relatively simple and inexpensive anaglyphs (color-filtered eyeglasses), liquid crystal shutter glasses, and complex, expensive head-mounted devices which have a dedicated display for each eye.
Certain problems are associated with providing 3-D effects in the computer field, including relatively large requirements for processing power, efficiency, and memory capacity. In many existing systems, these requirements stem from the fact that two separate images are generated for each frame that is rendered, i.e., one for the left eye and one for the right eye, compared to only one image per frame for conventional, two-dimensional (2-D) computer displays. For each frame to be rendered for 3-D display, the model geometry must be rendered from both eye points. Thus, each triangle in a scene is transformed, lit, set up, and rasterized twice for each frame. As a result, 3-D stereo applications must either execute at half the potential geometry rate or at half the potential frame rate. Either result tends to adversely impact the degree of realism experienced by the user. Hence, what is needed is a fast, efficient, and inexpensive technique for generating 3-D displays in a computer system.
The present invention includes a method of generating a stereoscopic sequence of frames. Each frame in the sequence has a left image and a right image. For at least one frame in the sequence, one of the left image and the right image is an approximation of the other image. In the method, any pixel not filled in the approximated image is assigned the data values of a corresponding pixel in an image from a preceding frame. Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.